Composite metal coin

ABSTRACT

COMPOSITE METAL COIN INCLUDING ONE OR MORE WIRE-LIKE ELEMENTS OF A MAGNETIC METAL OR ALLOY DISPOSED BETWEEN TWO PLATE-LIKE ELEMENTS OF A NON-MAGNETIC COIN METAL OR ALLOY OR A WEAK MAGNETIC METAL OR ALLOY AS COMPARED TO THE WIRE-LIKE ELEMENT, THE PLATE-LIKE ELEMENTS SURROUNDING THE WIRE-LIKE ELEMENT AND BEING JOINED AT THEIR INTERFACE, AND THE WIRE-LIKE ELEMENT EXTENDING FROM THE EDGE TO EDGE OF THE COIN. A METALLIC COATING CAN ALSO BE APPLIED AS BY ELECTROPLATING TO THE EXTERIOR OF THE PLATE-LIKE ELEMENTS.

3,597,23i if Oct. 10, 5 z

COMPOSITEMETAL COIN Filed Dec. 29, 1970 INVENTOR RICHARD SEFZ BURGESS. DINKLAGE & SPRUhKi ATTORNEYS.

United States Patent 3,697,237 COMPOSITE METAL COIN Richard Seiz, Bruchkobel, Germany, assignor to W. C. Heraeus GmbH, Hanan am Main, Germany Filed Dec. 29, 1970, Ser. No. 102,349 Int. Cl. A44c 21/00; G07f 1/06 US. Cl. 29-191 13 Claims ABSTRACT OF THE DISCLOSURE Composite metal coin including one or more wire-like elements of a magnetic metal or alloy disposed between two plate-like elements of a non-magnetic coin metal or alloy or a weak magnetic metal or alloy as compared to the wire-like element, the plate-like elements surrounding the wire-like element and being joined at their interface, and the wire-like element extending from edge to edge of the coin. A metallic coating can also be applied as by electroplating to the exterior of the plate-like elements.

BACKGROUND The present invention relates to a composite metal coin.

Metal coins are pieces of metal which are made in a certain form by order of and with the collaboration of the Government. Their purpose is to serve as means of payment. Ever since the minting of coins began, there have been constant attempts at self-aggrandisement by 9 the making and marketing of false coins, even though this is subject to penalty. It is known, for example, that 20 dollar gold pieces have been falsified by sawing genuine 20 dollar gold pieces in half and hollowing out or filing down both sides so that all that remains are thin shells of the obverse and reverse sides of the coin. Around these a rim is soldered and the void in between is filled with lead or a lead alloy. It is also known for genuine gold coins to be drilled at the margin and the hole filled with metal of lesser value and the location of the hole gilded.

The problem, therefore, has long existed of creating metal coins which are safer against counterfeiting than those made hitherto. This problem has acquired increasing importance in recent years since coin-operated vending machines and the like have gained in popularity.

Metal coins are known which are perforated to prevent counterfeiting. It is obvious that such measures provide but slight protection against falsification, and for this reason perforated coins have never been widely used.

SUMMARY The composite metal coin of the present invention com- THE DRAWING FIG. 1 shows a portion of a metal plate with an insert.

FIG. 2 shows a portion of a metal plate with two inserts.

FIG. 3 shows a composite coin blank according to the invention. I

FIG. 4 shows another composite coin blank according to the invention.

DESCRIPTION A coin of metallic material having at least one insert of metallic material is proposed, the material of the insert being different from the coin material enveloping the insert. This coin is characterized, according to the invention, in that the insert consists of a magnetic metal or a magnetic metal alloy and the coin material of a nonmagnetic metal or metal alloy or one which is only very weakly magnetic in comparison with the insert material.

In a preferred embodiment, the magnetic layer consists of at least one wire-like element or inlay which is enveloped by the two cover plates, the two facing surfaces of the cover plates being joined together by laminating for example. The use of a wire-like insert results in contrast to the coins known from French Pat. 1,565,964 for example in the advantage that the two cover plates can be joined together by lamination or the like. Also, when it comes to the magnetic-field sensing of coins with wirelike inserts according to the invention, better discrimination results from the production of pulses by self-induction when a plurality of inserts separated from one another by coin material is provided according to a preferred embodiment. This magnetic-field sensing is performed in coin-operated machines in order to distinguish genuine coins from counterfeit ones.

Steel and nickel-iron alloys have proven to be good magnetic insert materials. Suitable non-magnetic or very weakly magnetic coin materials are copper alloys, silver alloys, nickel alloys, titanium alloys or zirconium alloys, as well as titanium or zirconium. The invention is not limited to the above-named materials. The magnetic value of a coin made according to the invention can be predetermined by the appropriate selection of the insert material, the number of the inserts, their arrangement, and the width and thickness of the inserts, thereby providing extensive security against misuse. The coins of the invention can be magnetically sensed in automats, thereby achieving great safety against deception.

The manufacture of coins constructed according to the invention will now be described herewith, with the aid of preferred examples represented in the drawings.

Composite plates of metallic material are used as starting material for the manufacture of coin blanks according to the invention, portions of such plates being represented by way of example in FIGS. 1 and 2. These metal plates are made by sandwiching together two preferably equally thick sheets 1 and 2 of coin material with an inlaid insert 3 of magnetic material such as iron or iron alloy. In FIG. 1 the insert 3 is a round wire; in FIG. 2, two wires of rectangular cross section are provided which are spaced apart by coin material.

The coin blanks represented in FIGS. 3 and 4 are punched from such metal plates in a known manner. The portion of a plate of starting material that is represented in FIG. 2 differs according to the invention from the one represented in FIG. 1 not only in that two separate inserts are provided, but also in that the two plates 1 and 2 are additionally provided with a coating 4. This coating 4 consists of a metallic material, such as a gold alloy, for example, especially one that is more noble than the coin material of which the two plates 1 and 2 consists.

A coin blank such as the one shown for example in FIG. 3 can also, of course, be provided with a metal coating on all sides, by means of electroplating for example, or by non-electric deposition from a plating bath.

What is claimed is:

1. Composite metal coin currency comprising two outer plates joined at their interface and at least one wire-like insert enveloped between said outer plates,

the outer surface of each of said plates being substantially planar, l

said insert comprising a magnetic metal or alloy,

said outer plates comprising a (i) non-magnetic coin metal or coin alloy, or (ii) a coin metal or coin alloy which is weakly magnetic and substantially less magnetic than said insert. 7

2. The coin of claim 1 containing one insert and said insert extends from edge to edge of said coin.

3. The coin of claim 1 where said plates are at least one coin metal selected from the group consisting of copper alloy, silver alloy, nickel alloy, titanium alloy, zirconium alloy, titanium and Zirconium.

4. The coin of claim 3 wherein said insert is at least one magnetic metal selected from the group consisting of magnetic steel, and iron-nickel alloy.

5. The coin of claim 1 containing a plurality of inserts, each of said inserts being separated from another insert by coin metal of said outer plates.

6. The coin of claim 5 where said plates are at least one coin metal selected from the group consisting of copper alloy, silver alloy, nickel alloy, titanium alloy, zirconium alloy, titanium and zirconium.

7. The coin of claim 6 wherein said inserts are at least one magnetic metal selected from the group consisting of magnetic, steel, and iron-nickel alloy.

8. The coin of claim 5 wherein said inserts are at least one magnetic metal selected from the group consisting of magnetic steel, and iron-nickel alloy.

9. The coin of claim 7 wherein said plates are of the same thickness, and wherein each of said plurality of inserts is parallel to the others.

10. The coin of claim 2 wherein said plates are of the same thickness, and wherein each of said plurality of inserts is parallel to the others.

11. The coin of claim 8 wherein said composite coin is completely enveloped in a metal coating.

12. The coin of claim. 2 wherein said composite coin is completely enveloped in a metal coating.

13. The coin of claim 12 wherein said metal coating is of a material which is more precious than the said material of said plates.

References Cited UNITED STATES PATENTS 3,406,446 10/1968 Muldovan 29-1914 X 3,419,952 1/1969 Carlson 29191.4 X 1,125,162 1/1915 Page 29l91.4

ALLEN B. CURTIS, Primary Examiner US. Cl. X.R. 17.5 

